Social Meaning and the Cult of Tim

In a previous column, "The Social
Meaning of RDF", I described a debate about the relation of
formal and social meanings of RDF assertions, particularly as
related to the Semantic Web. This debate about the "social meaning
of RDF" is complex and encompasses a wide range of thorny issues.

Not only does the debate have many conceptual parts, but it also has
many modalities. Last time I discussed it in this column I was
focusing on an upcoming technical plenary session at the W3C, where
the social meaning issues were on the
agenda. The issue before that tech plenary was whether to strike
or edit section 4 of the RDF Concepts and Abstract
Syntax specification. This way of carrying on the social
meaning debate was unlikely to lead to a satisfactory resolution,
since it was possible to strike the problematic language without solving or
addressing the substantive issues which animate the debate in the first
place.
Some of those issues include
the following:

how or whether the meaning of URIs (when used, for example, as
RDF predicates) is defined and defined authoritatively;

how one asserts, or refrains from asserting, RDF
statements;

how one specifies the meaning of an RDF graph, which presupposes
some position on the relation of an RDF graph's formal meaning,
social meaning, and social meaning of its "formal entailments";

whether the social meaning of RDF assertions is a function of
the intention of the speaker ("speaker meaning") or is a function of
the meaning of the assertion itself ("sentence meaning");

whether "publishing" RDF is sufficient to obligate someone
(anyone?) to its formal or social meanings; if so, who does it
obligate and what sort of obligation is it; and, further, what acts
or ommissions constitute a party as the "publisher" or as the
"asserter" of some RDF;

what relation there is between RDF's meaning, whether social or
formal, and legal contexts and considerations.

In other words, all the really easy stuff....

The participants of the plenary session reached a
broad consensus, which consisted of four points, two of which
are especially relevant here: first, that section 4 of the Concepts
document would be struck; second, that the Semantic Web Coordination
Group (SWCG) would "prioritize work on this issue, coordinated with
the TAG over URI denotation". As has become clear, however, there
seems to have been some ambiguity about the substance of this
consensus, particularly related to the role of the SWCG, about which
more below.

Apparently in response to the tech plenary and to SWCG discussions,
Tim Berners-Lee recently
proposed the social meaning cluster as a new TAG issue. Dan
Connolly says
that the SWCG kicked the issue up to the TAG because it "didn't see
a way to specify how this works for RDF without specifying how it
works for the rest of the Web at the same time".

There have been at least two different kinds of objections to
Berners-Lee's request that the TAG take on the social meaning issue
(though, to be fair, I'm not entirely sure what precisely
Berners-Lee intended the TAG to consider, given that his message is
confusing and seems to have been written haphazardly.) The first
kind is procedural: that Berners-Lee's actions are not fully
responsive to the tech plenary consensus. The second kind is
substantive: that Berners-Lee's statement of the social meaning
problem in his message to the TAG is simply wrong and misleading .

Substantive Questions

Pat Hayes -- who, it must be
pointed out, is an important player not only in the Semantic Web
effort but also in the recent history of knowledge representation
and artificial intelligence research -- voiced the most sustained
substantive criticism of Berners-Lee's presentation of the social
meaning issue. In Hayes' estimation, Berners-Lee's presentation of
the social meaning issue contained several falsehoods: "To make
authoritative assertions of propositions which are clearly or
provably false", Hayes claimed, "does not make them true; it only
destroys public trust in the source making the silly assertions".

What are some of these falsehoods, according to Hayes? First,
Berners-Lee says that "each URI identify [sic] one thing
("Resource": concept, etc)". But if, as Hayes points out, "identify"
means reference or denotation, then "it is simply untenable to claim
that all names identify one thing."

Berners-Lee also claims that his understanding of the Semantic Web
architecture "allows information to be published so that the
recipient of an RDF statement 'S P O' [i.e., a subject, predicate,
object RDF triple] can, by dereferencing P, get information about
the relation being asserted." Hayes's response is worth quoting in
full:

Wrong. First, there is no particular semantic importance attached to
the P part of the triple. Properties have no special status in RDF.
Second, the relation is not being asserted: the triple is. Third,
there is no particular reason why dereferencing P will get you to
the information you might require in order to draw the appropriate
conclusions; and indeed most RDF applications would not work if this
were an architectural requirement. Finally, this conclusion does not
follow from the architectural points made previously.

Hayes makes other substanitive criticisms of Berners-Lee's position,
and I suggest that interested parties study his message (and the
entire thread in which it occurs) carefully. Hayes finished his
criticism of Berners-Lee by striking a note to which I will return
below, one about the clash of professional competencies,
expectations, and standards:

Maybe, if I could make the suggestion without seeming to commit
lese-majesty, it would be a good strategy for the W3C, rather than
trying to render nonsense "in terms that the ontology community will
understand," to ask if it might possibly learn something from
actually listening to the ontology community; or at any
rate, to anyone with a grasp of basic 20th-century results in
linguistic semantics.

In response to Hayes's overarching claim about substantive
falsehoods, Berner's Lee
said that he was "using English, not model theory. You [i.e.,
Hayes] use model theory words, but it may be that model theory can't
express the English talking about for example the real world." In
response to Hayes's claim that there is ambiguity (and falsity all
possible readings of that ambiguity) in the claim that "each URI
identify [sic] one thing", Berners-Lee said that "... I am
describing, if you like, a perfect platonic design, to which we can
aspire, though social and engineering factors limit our ability to
implement it perfectly ... One deals with deviations from the perfect
in a form of perturbation theory." And in response to Hayes's claim
that the predicate element of an RDF triple is not semantically
special, Berners-Lee retorts that "p is associated with the
relation. I had understood that the semantics of s p o were the
relation R(s,o) where R is identified by p. Did I get it the wrong
way around?"

In general Berners-Lee's responses suggest, when they do not
outright claim, that Hayes is simply unfamiliar with the merits of
engineering fixes to the conceptual problems he
identifies. Berners-Lee suggests this in a series of statements,
which to my ear have an unhelpfully arrogant tone, in his response
to Hayes:

We will always be a challenge for those of you who make these
precise theories.

It is maybe from working with these [operators like multiplication
and addition], and with the well-known and quite non-URI-like
properties of natural language words, that you may have become blind
to the advantages of an architecture where we say "This system is
different from natural language: we design it such that each URI
identifes (doenotes?) [sic] one and only one concrete thing in the
real world or one and only one globally shared concept".

...we are not analyzing a world, we are building it. We are not
experimental philosophers, we are philosophical engineers. We
declare "this is the protocol". When people break the protocol, we
lament, sue, and so on. But they tend to stick to it because we show
that the system has very interesting and useful properties (emphasis
added).

The architecture...defines an "authoritative" or "definitive"
meaning, to which "meaning" in wittgensteinian sense and "intended
menaing" in [an] ethical or legal sense generally approach as
closely as they can, and close enough for the system to work and be
unbelievably useful to millions of people.

We are building a new system. We can design it differently from
existing linguistic systems. Toto, we are not in Kansas any more.

Hayes's response to Berners-Lee's response clarifies some of the
disputed issues. As to Berners-Lee's equivocation that URIs
"uniquely identifying one thing" is an ideal which can only be
imperfectly approximated in actual systems, Hayes's response is very
blunt:

I'm not saying that the "unique identification" condition is an
unattainable ideal: I'm saying that it doesn't make sense, that it
isn't true, and that it could not possibly be true. I'm saying that
it is crazy.

Procedural Questions

In addition to these and other substantive issues, there are
procedural problems floating around. I have concluded, after
studying the relevant documents and speaking with participants, that
the consensus reached at the tech plenary was underspecified. There
are at least three procedural issues: first, does Berners-Lee's
making a request to the TAG to consider the social meaning issue
accurately reflect the tech plenary consensus (this is distinct from
the substantive issue of whether the content of
Berners-Lee's message is either adequate or fair to those who do not
share his position); second, is the TAG really the appropriate
setting in which to resolve this issue; third, is there something
broken about the W3C's institutional or moral authority?

The Tech Plenary Consensus

Part of the tech plenary's consensus was to ask the Semantic Web
Coordination Group to do
something about the social meaning issue. It isn't clear what
the SWCG was supposed to do, precisely. Some of the interested
parties think that the SWCG was supposed to determine the priority
of this issue, others that it was supposed to work on this issue
itself, giving it a high priority. Yet others think that the
SWCG was supposed to give a high priority to forming some kind of
group to determine whether and what could be actually said about the
issue that could get consensus.

Berners-Lee's request to the TAG is that "a draft finding be written
which pulls this together [i.e., presumably, his view of what needs
to be done about the social meaning issue], with elaborations
pointing into the various specs. Members of the SWCG have
volunteered and some members of the SWCG have been volunteered to
read early versions." Note that he doesn't say who or what might
author this draft finding. And, as we'll see, using Berners-Lee's
disputed reading of these issues as the basis for a draft finding is
problematic.

Is the TAG Appropriate?

I'm not sure the TAG is the right venue or context within which to
decide this issue. There is, however, at least one reason for the
TAG having some hand in the resolution, namely, that the SWCG claims
that the problems of URIs and resources are not specific to RDF, but
touch the existing Web. That sort of large architectural issue --
though it's not clear that this is an architectural issue as much as
it is a problem of formal specification -- is certainly within the
TAG's purview.

There are at least two reasons why the TAG may not be the ideal
place to resolve the social meaning debate. First, most, if not all
of the TAG members are software engineers of one kind or
another. The debate about social meaning is in some ways a
debate between at least two distinct kinds of computer professional:
the software engineers (who make a legitimate claim to have built
the Web in the first place) and the knowledge representation
theorists (who make a legitimate claim to have built many knowledge
representation systems of a kind analogous to the one which the
Semantic Web is meant to become.)
Not only do these groups have
different methods, backgrounds, and modes of argument and
discourse, but they also have divergent expectations and standards
about formalisms, formal systems, and the like.

Giving the issue over to the TAG to resolve entirely seems like a
bit of procedural game-rigging, whether intentional or not. Of
course someone will object at this point that the TAG is open to
input from people other than its members. That's true, but that
fact may not be enough to ensure that the process of resolving this
debate is substantially open and fair and, as importantly, is seen
to be substantially open and fair.

There has been a process question here, which we might express as a
continuum. At one end, the W3C could convene a series of Semantic
Web Design Workshops to try to come up a viable design for the
Semantic Web. At the other end, it could go with [Berners-Lee's]
intuition that the Semantic Web is deeply coherent with the existing
Web, and that URIs have always been logical constant symbols. What
[Berners-Lee is] asking the TAG to do here, I think, is to use his
sketch as the initial straw man. Some of the motivation here is
surely the fear that the other end of the spectrum is a very, very
slow road. More a bog, really.

In this regard, Hawke makes an able stand-in for the concerns of the
software engineers, namely, that KR theorists can formalize the
process to death. But surely at the other end of this continuum
there is also a danger? The KR theorists are likely to respond that,
given the deep flaws in Berners-Lee's "initial straw man" proposal,
that the process of resolving the issue will be poisoned from the
start. Or, put another way, since the Semantic Web is really meant
to be a distributed, decentralized knowledge representation system,
built a top the existing Web -- itself a distributed, decentralized
hypermedia system -- it simply is the case that conceptual muddles,
of the sort KR theorists like Pat Hayes claim Berners-Lee has fallen
into, are serious and practical obstacles to realizing the Semantic
Web.

There is an internally powerful bit of W3C institutional lore
which is relevant here and surely serves as motivation, not only for
Berners-Lee but for those who defend his "intuition." This is that
hypertext and hypermedia theorists were so hung up on
building perfect systems that they couldn't get something like "the
Web" as we know it today built; the flip side of this legendary tale
is that it took a practical, hard-minded software engineer like
Berners-Lee to come along and build a practical, workable system
like the Web. Hawke refers directly to this story as the "web's
founding mythos," one which serves as a powerful internal motivation
for W3C members and proponents.

The Cult of Tim

Weaving throughout this tangle of competing claims and
understandings is the social fact of Berners-Lee's institutional and
moral authority. For the record, I do not dispute that Berners-Lee
deserves some measure of moral authority, owing to his role in
bringing the Web to life. The question, however, is how far that
moral authority should be allowed to extend and whether it implies
any other special abilities or capacities.

Perhaps the most disturbing aspect of the entire social meaning
debate is the degree to which people uncritically defer to
Berners-Lee's "intuition" and "vision", that is, to his admittedly
incompletely expressed idea about the Semantic Web. Few people think
that Berners-Lee's ideas about the Semantic Web are perfectly or
completely formed. Everyone, including Berners-Lee himself, agrees
that they are intuitions, which implies the idea that he can see
further than he can say, that he can reach further than he can
grasp, at least for now.

One obvious point to make is that there are a lot of people trying
to help Berners-Lee realize his intuited vision and that he wields
more influence and authority over this complex process than any
other single person. Perhaps that is perfectly
appropriate. However, the problem arises when other people, who have
less moral authority, disagree with Berners-Lee. I have heard it
said several times, although few people seem willing to commit to
this view publicly, that Berners-Lee should be exempt from
public criticism because the realizability of the Semantic Web
rests upon Berners-Lee's reputation more than upon any other single
factor.

That viewpoint not only cedes to legitimate moral authority far,
far too much ground, but it also threatens the credibility of the
entire Semantic Web effort. No one should be exempt from public
criticism. Let me say that again, clearly: neither Tim Berners-Lee
nor anyone else should be exempted from fair, balanced, charitable
public criticism. Having created the Web does not in itself mean
that Berners-Lee is right about every issue, as he would freely
admit. Nor does it mean that people who disagree should "defer to
the vision" of Berners-Lee. Too many W3C groupies, hangers-on,
associates, employees, and peripheral figures act as if
Berners-Lee's "vision" is infallible or incorrigible. I have heard
W3C people react harshly to criticism of Berners-Lee on precisely
these terms. "After all", they suggest, "he did invent the
Web". Playing on that bit of institutional lore aforementioned, the
idea seems to be that "Tim did it once, only Tim can do it again".

I'm not going to spend much time here suggesting why that idea is
flawed. I will suggest, however, that the existing Web is an
exceedingly complex entity and that its realization required the
work of hundreds of very smart people. Nothing as complex as the Web
is ever the result of one person's work alone. The Semantic Web
will be, if it can be achieved at all, significantly more complex
than the existing Web. It will no more be the result of one person's
efforts than the Web is. We do ourselves, the Semantic Web effort,
and Tim Berners-Lee a real disservice insofar as we contravene these
basic facts.